①在IDE中建立Maven web專案

②匯入mybatis jar包

<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>

③在專案的resources目錄下新建mybatis-config.xml配置檔案

配置檔案的內容可以參考mybatis原始碼包中的配置檔案

mybatis原始碼包的下載地址：

具體路徑為：

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/javajdbctest"/>
<property name="username" value=""/>
<property name="password" value=""/>
</dataSource>
</environment>
</environments>
</configuration>
 

④獲取資料庫最最核心的類SqlSession

public SqlSession getSqlSession() throws IOException {
//通過配置檔案獲取資料庫連線資訊
Reader reader = org.apache.ibatis.io.Resources.getResourceAsReader("mybatis-config.xml");
//通過配置資訊構建一個SqlSessionFactory
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
//通過sqlSessionFactory開啟一個數據庫會話
SqlSession sqlSession = sqlSessionFactory.openSession();
return sqlSession;}
 

⑤編寫customer簡單java類

public class Customer {
    private int id;
    private String name;
    private String address;
    private String phone;
    
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public Customer() {
    }

    public Customer(int id, String name, String address, String phone) {
        this.id = id;
        this.name = name;
        this.address = address;
        this.phone = phone;
    }

    @Override
    public String toString() {
        return "Customer{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", address='" + address + '\'' +
                ", phone='" + phone + '\'' +
                '}';
    }
}
 

⑥資料庫的中customer表

命名不是很規範（用於測試，忽略不計）

⑦建立資料庫與Javabean關聯的配置檔案

同樣可以參考在步驟③中的路徑下的User.xml檔案

新建CustomerMapper.xml配置檔案:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--namespace相當於包的含義-->
<mapper namespace="Customer">
    <!--type是customer類所在包的路徑-->
    <resultMap type="algorithm.offer.pojo.Customer" id="CustomerResult">
        <id column="id" jdbcType="INTEGER" property="id"/><!--主鍵用id-->
        <result column="name" jdbcType="VARCHAR" property="name"/>
        <result column="address" jdbcType="VARCHAR" property="address"/>
        <result column="phone" jdbcType="VARCHAR" property="phone"/>
    </resultMap>
    <!--id為此SQL語句的唯一標識，resultMap與resultMap相對應-->
    <select id="findCustomerList" parameterType="long" resultMap="CustomerResult">
        SELECT id,name,address,phone FROM customer
    </select>

</mapper>

⑧mybatis-config.xml與CustomerMapper.xml的關聯

將以下程式碼寫在mybatis-config.xml檔案中:

<mappers>
        <mapper resource="MybatisMapper/CustomerMapper.xml"/>
    </mappers>

⑨編寫DAO層Service層

DAO層

/**
 * Customer的DAO層
 */
public class CustomerDAO {
    DBAccess dbAccess = new DBAccess();

    /**
     * 查詢所有Customer
     * @return
     */
    public List<Customer> findCustomerList(){
        List<Customer> customerList = new ArrayList<>();
        SqlSession sqlSession = null;
        try {
            sqlSession = dbAccess.getSqlSession();
            customerList = sqlSession.selectList("Customer.findCustomerList");
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if (sqlSession!=null){
                sqlSession.close();
            }
        }

        return customerList;
    }
}

service層

public class CustomerService {
    /**
     * 查詢所有消費者資訊
     * @return
     */
    public List<Customer> showCustomer(){
        CustomerDAO customerDAO = new CustomerDAO();
        return customerDAO.findCustomerList();
    }


}

⑩測試

 @Test
    public void showCustomer() throws Exception {
        CustomerService customerService = new CustomerService();
        for (Customer customer:customerService.showCustomer()) {
            System.out.println(customer.toString());
        }
    }